1. Field of the Invention
The present invention relates to a fingerprint recognition method, and more particularly, to a coding method of a fingerprint image that accurately converts a fingerprint image into a binary code to detect a featured vector required for recognizing the fingerprint. The coding method accurately removes image flaws and recovers fingerprint ridges with reference to the original image of the fingerprint.
2. Description of the Related Art
In recent years, a variety of personal certifying methods use a user's iris, fingerprint, face profile, and the like to determine identity. Biometrics use of fingerprint recognition has increased due to the simple nature of obtaining fingerprints and because the recognition time of a fingerprint image is short.
Conventional fingerprint image methods detect and convert a fingerprint image into a binary code to produce, for example, a monochrome image.
Conventional binary coding methods, using a single threshold, detect from the whole image using an upper and lower limit of the single threshold defined for binary-coding the image. To define the background area and solve brightness uniformity problems incurred during image detection, a conventional binary coding method has been proposed that detects local thresholds and converts locally the image into a binary code, for example, a black and white image.
As described above, conventional binary coding methods may use a variable threshold to produce a printable and storable binary image that accurately represents the fingerprint image. However, these conventional methods have disadvantages when a feature vector is detected and a fingerprint comparison is performed. For example, when a ridge of a fingerprint is recognized in a variety of user's features according to its circumference, the accuracy of fingerprint recognition is deteriorated.
Conventional binary coding methods may not effectively repair damage to a fingerprint image. For example, junctions or breaks in a ridge of a fingerprint image or other image flaws may cause fingerprint image recognition errors and result in failed fingerprint image recognition.
An inaccurately coded binary image complicates problems associated with image post-processing.